Discussion

MH finished his talk with the conclusion that Beached Bird Surveys (BBS) can certainly be used to measure the effectiveness of steps taken to combat chronic oil pollution at sea. The most obvious lesson learned from the BBS on Shetland is that oil terminals should not be opened without the establishment of ballast reception facilities. Looking at the Shetland BBS, with hindsight, surveys should have been started up earlier to provide more baseline data and there should have been a better system for sampling oil from both plumage and beaches. The talk covered 1976-1983, but a similar programme still goes on on Shetland. It is allowed to discharge small amounts of oil in the North Sea. GD concluded that the mere presence of a discharge limit could lead to illegal discharges. The reason is, that discharge limits cannot be met nowadays. In a detailed study, testing monitoring equipment on board ships, it was found that while the maximum concentration of oil in a bilge water discharge should be between 15 and 100 ppm (MARPOL Convention), it averaged 450 ppm with a maximum of 54,000 ppm. If oil discharges over 15 ppm are totally forbidden, which would be the case when the North Sea was declared ’Special Area’ according to MARPOL standards, all detected oil slicks refer to illegal shipping/offshore operations.